The present invention relates to a solid electrolytic capacitor having a plurality of mounting terminals serving as electrodes.
Recently, devices and apparatuses in various fields are making progress towards a smaller size, a thinner profile, and a higher performance. As one of effective approaches therefor, it is proposed to use a high frequency as a driving frequency of a circuit. For example, in case of a solid electrolytic capacitor used as a power supply circuit of an apparatus, the capacitor must have a low inductance (hereinafter referred to as ESL (equivalent series inductance)) so as to be adapted to a high frequency.
The ESL is increased due to various factors, such as a permeability of a conductor inside the device, a wiring length from the inside of the device to mounting terminals, and a wiring pattern. In order to reduce the ESL, a distance between positive and negative mounting terminals is reduced so as to decrease an inductance component, called a loop inductance, produced between the positive and the negative terminals. Recently, use is frequently made of techniques of increasing the number of mounting terminals and disposing the positive and the negative terminals in one-dimensional alternate arrangement or in a two-dimensional staggered arrangement. Hereinafter, such a capacitor having an increased number of mounting terminals will be called a multi-terminal capacitor.
For example, the multi-terminal capacitor is disclosed in Japanese Unexamined Patent Application Publication (JP-A) No. 2002-343686 as a solid electrolytic capacitor. The solid electrolytic capacitor comprises a porous valve metal sheet member having one surface provided with a plurality of electrode portions, a dielectric film formed on a porous portion of the valve metal sheet member, a solid electrolyte layer formed on the dielectric film, and a power collector layer formed on the solid electrolyte layer. The solid electrolytic capacitor is provided with through holes extending between one side provided with the electrode portions and the other side provided with the power collector layer. Each of the through holes is filled with an insulator. At a center portion of the insulator, a conductor is disposed to be electrically connected to the power collector layer or the electrode portion.
In the above-mentioned solid electrolytic capacitor, the ESL is lowered as the number of the electrode portions increases. However, during processing for arranging the conductor at the center portion of the insulator, capacitor characteristics tend to be deteriorated. In addition, production is not easy and mass-production is difficult.